The impacts of tourism, most notably food resource enrichment and harassment, have led to alterations in natural bear (Ursus sp.) behavior in many National Parks throughout the United States. Comprehensive efforts to reduce these impacts and restore natural activity patterns have been elements of US National Park management for decades. We described black bear (U. americanus) activity patterns during 2001 and 2002 to assess the influence of human activity centers on bear behavior in Yosemite National Park, California, USA. We found bear activity and movement patterns, habitat use, and the distance bears were located from developed areas continued to be influenced by human presence in the Yosemite Valley region of Yosemite National Park. We recommend continued use of educational campaigns, stronger law enforcement efforts, improvements to food storage containers, more effective waste management, and more aggressive aversive conditioning techniques to reduce the number of human–bear interactions and restore the natural behavioral elements of Yosemite's black bear population.